"There was no discussion about it, we never talked about it, we just, we hired Jai on the spot," he says.

For Courtney, getting the villainous role of Charlie in Jack Reacher was something of a break into Hollywood movies.

"It was certainly a welcome gig to get after a couple of years of not working - and a fantastic project," says Courtney, who last appeared in TV series Spartacus.

Since getting cast in Jack Reacher, the thriller based on Lee Child's book series, Courtney has acted opposite Bruce Willis, playing his son in A Good Day to Die Hard, and scored roles in I, Frankenstein with Aaron Eckhart and in the Aussie film Felony.

With all these films slated for release this year, or beyond, you sense it must feel like the calm before the storm.

"I've had some incredible experiences in the last year or so and [am] just embracing that."

He says he's not really thinking about whether he will lose his anonymity, admitting he's a little naive about it and will just see how he handles it when or if it happens.

Meanwhile, McQuarrie says he couldn't be happier that Courtney, who he describes as a genuinely good soul, has gone on to such success.

"You work with somebody very closely and somebody that you feel some sense of having a part in discovering that person and then to have other people step up and validate what you saw is great," he says.

"I'm just thrilled for Jai."

While Jack Reacher is McQuarrie's second time directing, he is a seasoned screenwriter, having won an Oscar for penning 1995 film The Usual Suspects.

But aside from the great script, for Courtney scoring the role of Charlie also marked something of a first.

"This was kind of the first villain I had played," he says.

"Of course there's [also] the whole boys with their toys thing. I get to shoot guns and drive cars," he says. "It's a dream come true."

To prepare for some of the stunts, Courtney needed to train with weapons, particularly sniper rifles, and learned choreographed fights.

He first met Cruise when he dropped by during a fight rehearsal.

"I was like sweaty and in my trackpants and he kind of rolled in and yeah, you have one of those moments where it was like [looking starstruck], 'hey, how you doing, man,"' he says.

"But soon after that you find yourself in a meeting and you're discussing the role ... and it's just a colleague."

As for working with Cruise, compared to working with Willis, Courtney says the experiences were totally different, but equally enjoyable.

"Bruce was a lot of fun to work with," he says.

"In some ways [I] had a lot more to do with Bruce than I did with Tom, in just the nature of those characters and the journey in the script of the Die Hard film."